A piece of wire 40 cm long is to be cut into two pieces. One piece will be bent to form a circle and; the other will be bent to form a square. Find the lengths of the two pieces that cause the sum of the area of the circle and the area of the square to be a minimum. The perimeter of the square is cm The circumference of the circle is cm

Step-by-step explanation:

The total length of the wire  = 40 cm

Let us assume the circumference of the circle  = k cm

So, the circumference of the square  = ( 40 - k) cm

Now,as circumference of circle = 2πR

⇒2πR = k cm    or, R  =

Area  of the  circle = πR²  

or, A  =  

    ....... (1)

Similarly , perimeter of square  = 4 x Side

⇒ 4 x Side  =  ( 40 - k) cm    ⇒ S =

Area  of the  square = (Side)²    =

 Solving, we get:     ....... (1)

So, combining (1) and (2), total area A is

or, we get: A  = 0.07962 k²  + 0.0625 k² + 100 - 5 k

A  =  0.1422 k² - 5 k + 100

For axis of symmetry :  

⇒ k = 17.6 inches

So, the perimeter of circle  = 17.6 cm

Perimeter of square  = (40 - 17.6 )  = 22.4 cm

look at the picture i have filled out a table for it. hope this .